Nysza III, also known plainly as Nysza, existed as a planetary body within the Outer Rim Territories, specifically within the bounds of the Dalchon sector. The Galactic Empire once initiated building a communications bunker upon it. However, by the time period of 0 ABY, the Rebel Alliance's Harrier Infiltration Team, acting under the command of captain Fable Astin, had destroyed that very structure.
Nysza III, which could also be referred to as simply Nysza, was a planet that was located in the Nysza system of the Outer Rim Territories' Dalchon sector, and was near the planet Iscera of the Iscera system.

At a point in time before 0 ABY, the Galactic Empire initiated the construction of a communications bunker on Nysza III, and a garrison was stationed there. In that year, Commander Beatonn of the Rebel Alliance used a hologram to communicate with the Rebel Harrier Infiltration Team and its captain, Fable Astin, assigning the team the task of destroying the Nysza III bunker before it was finished.
While the mission was ultimately a success, the team's technical officer Arecelis Acosta met their death. Astin and her Rebel companion Deke Holman then made their escape from the bunker—being compelled to submerge themselves in a construction tunnel filled with stagnant water during their escape—and traveled to Iscera aboard their light freighter called the Prodigal. Around seventeen hours after the mission's end, Astin deleted the stored message from Beatonn that mentioned Nysza III. Shortly after, while still aboard the Prodigal, Astin experienced a nightmare in which she re-experienced a twisted version of the mission to Nysza III.
Nysza III was first seen in a dream within the short story "Uhl Eharl Khoehng," penned by Patricia A. Jackson and featured in the November 1995 eighth issue of West End Games' Star Wars Adventure Journal magazine. The shortened name of the planet was introduced in 2008's The Complete Star Wars Encyclopedia, and the 2009 reference book The Essential Atlas located the Nysza system, and by extension Nysza III, in grid square R-17.